One of the core competencies of the ENCRYPTO group is building tools that make efficient secure multi-party computation accessible to non-experts. We make our tools available as open source and they are used by several research groups and industry.

Awards

• 2017 CROSSING Collaboration Award: Daniel Demmler and Christian Weinert from the ENCRYPTO Group together with Felix Günther, Stefan Krüger, and Michael Reif won the CROSSING Collaboration Award 2017 for their joint paper “CogniCrypt: Supporting Developers in using Cryptography”.
• 2016 CROSSING Collaboration Award: Daniel Demmler and Michael Zohner from the ENCRYPTO Group together with Ghada Dessouky and Shaza Zeitouni won the CROSSING Collaboration Award 2016 for their joint research on tools for multi-party computation.

Publications (selection)

• N. Büscher, D. Demmler, S. Katzenbeisser, D. Kretzmer, T. Schneider. HyCC: Compilation of hybrid protocols for practical secure computation. In 25. ACM Conference on Computer and Communications Security (CCS'18), 2018. Code: https://gitlab.com/securityengineering/HyCC. Acceptance rate 16.6%. CORE rank A*.
• M. S. Riazi, C. Weinert, O. Tkachenko, E. M. Songhori, T. Schneider, F. Koushanfar. Chameleon: A hybrid secure computation framework for machine learning applications. In 13. ACM Asia Conference on Information, Computer and Communications Security (ASIACCS'18), 2018. Acceptance rate 16.8%. CORE rank B.
• G. Dessouky, F, Koushanfar, A.-R. Sadeghi, T. Schneider, S. Zeitouni, M. Zohner. Pushing the communication barrier in secure computation using lookup tables. In 24. Annual Network and Distributed System Security Symposium (NDSS'17), 2017. Acceptance rate 16.1%. CORE rank A*.
• D. Demmler, G. Dessouky, F. Koushanfar, A.-R. Sadeghi, T. Schneider, S. Zeitouni. Automated synthesis of optimized circuits for secure computation. In 22. ACM Conference on Computer and Communications Security (CCS'15), 2015. Acceptance rate 19.8%. CORE rank A*.
• E. M. Songhori, S. U. Hussain, A.-R. Sadeghi, T. Schneider, F. Koushanfar. TinyGarble: Highly compressed and scalable sequential garbled circuits. In 36. IEEE Symposium on Security and Privacy (IEEE S&P'15), 2015. Acceptance rate 13.5%. CORE rank A*.
• D. Demmler, T. Schneider, M. Zohner. ABY – a framework for efficient mixed-protocol secure two-party computation. In 22. Annual Network and Distributed System Security Symposium (NDSS'15), 2015. Code: https://encrypto.de/code/ABY. Acceptance rate 18.4%. CORE rank A*.
• F. Kerschbaum, T. Schneider, A. Schröpfer. Automatic protocol selection in secure two-party computations. In 12. International Conference on Applied Cryptography and Network Security (ACNS'14), 2014. Acceptance rate 22.4%. CORE rank B.
• W. Henecka, T. Schneider. Faster secure two-party computation with less memory. In 8. ACM Symposium on Information, Computer and Communications Security (ASIACCS'13), 2013. Code: https://encrypto.de/code/me-sfe. Acceptance rate 16.2% for full papers. CORE rank B.
• T. Schneider, M. Zohner. GMW vs. Yao? Efficient secure two-party computation with low depth circuits. In 17. International Conference on Financial Cryptography and Data Security (FC'13), 2013. Acceptance rate 12.5% for regular papers. CORE rank B.
• W. Henecka, S. Kögl, A.-R. Sadeghi, T. Schneider, I. Wehrenberg. TASTY: Tool for Automating Secure Two-partY computations. In 17. ACM Conference on Computer and Communications Security (CCS'10), 2010. Code: https://encrypto.de/code/TASTY. Acceptance rate 17.2%. CORE rank A*.

Privacy-preserving machine learning allows to run machine learning algorithms while protecting both the data and the models. This can be achieved by using secure computation techniques.

Awards

• 2019 Intel Research Award: The ENCRYPTO group was awarded by Intel Corporation for our research in the area of “Secure and Privacy Preserving AI Frameworks and Run-Times for Data Scientists and Service Providers”.

Publications (selection)

• T. Schneider. Engineering Privacy-Preserving Machine Learning Protocols. Privacy-Preserving Machine Learning in Practice (PPMLP) – CCS'20 Workshop, Keynote, 2020.
• R. Cammarota, M. Schunter, A. Rajan, F. Boemer, Á. Kiss, A. Treiber, C. Weinert, T. Schneider, E.l Stapf, A.-R. Sadeghi, D. Demmler, H. Chen, S. U. Hussain, S. Riazi, F. Koushanfar, S. Gupta, T. S. Rosing, K. Chaudhuri, H. Nejatollahi, N. Dutt, M. Imani, K. Laine, A. Dubey, A. Aysu, F. S. Hosseini, C. Yang, E. Wallace, P. Norton. Trustworthy AI Inference Systems: An Industry Research View. Technical Report, 2020.
• F. Boemer, R. Cammarota, D. Demmler, T. Schneider, H. Yalame. MP2ML: A mixed-protocol machine learning framework for private inference. In 15. International Conference on Availability, Reliability and Security (ARES'20), 2020. Acceptance rate 21.3%. CORE rank B.
• A. Treiber, A. Molina, C. Weinert, T. Schneider, K. Kersting. CryptoSPN: Privacy-preserving sum-product network inference. In 24. European Conference on Artificial Intelligence (ECAI'20), 2020. Acceptance rate 26.8%. CORE rank A.
• S. P. Bayerl, T. Frassetto, P. Jauernig, K. Riedhammer, A.-R. Sadeghi, T. Schneider, E. Stapf, C. Weinert. Offline model guard: Secure and private ML on mobile devices. In 23. Design, Automation & Test in Europe Conference & Exhibition (DATE'20), 2020. Acceptance rate 26%. CORE rank B.
• R. N. Reith, T. Schneider, O. Tkachenko. Efficiently stealing your machine learning models. In 18. Workshop on Privacy in the Electronic Society (WPES'19), 2019. Acceptance rate 20.9%.
• Á. Kiss, M. Naderpour, J. Liu, N. Asokan, T. Schneider. SoK: Modular and efficient private decision tree evaluation. Proceedings on Privacy Enhancing Technologies (PoPETs), 2019. Code: https://encrypto.de/code/PDTE. Acceptance rate 21.1%. CORE rank B.
• M. S. Riazi, C. Weinert, O. Tkachenko, E. M. Songhori, T. Schneider, F. Koushanfar. Chameleon: A hybrid secure computation framework for machine learning applications. In 13. ACM Asia Conference on Information, Computer and Communications Security (ASIACCS'18), 2018. Acceptance rate 16.8%. CORE rank B.
• M. Barni, P. Failla, R. Lazzeretti, A.-R. Sadeghi, T. Schneider. Privacy-preserving ECG classification with branching programs and neural networks. IEEE Transactions on Information Forensics and Security (TIFS), 2011. CORE rank A.
• M. Barni, P. Failla, V. Kolesnikov, R. Lazzeretti, A.-R. Sadeghi, T. Schneider. Secure evaluation of private linear branching programs with medical applications. In 14. European Symposium on Research in Computer Security (ESORICS'09), 2009. Acceptance rate 19.1%. CORE rank A.
• A.-R. Sadeghi, T. Schneider. Generalized universal circuits for secure evaluation of private functions with application to data classification. In 11. International Conference on Information Security and Cryptology (ICISC'08), 2008. Acceptance rate 19.8%. CORE rank B.

Private set intersection (PSI) allows two or multiple parties to jointly compute the intersection of their input sets without leaking any information about elements that are not in the intersection. PSI has many applications such as contact discovery in mobile messengers like Signal or Whatsapp, or measuring ad conversion rates as run by Google and merchants. We are mostly interested in improving the efficiency of PSI protocols for practical applications. Watch our explanatory video on YouTube.

Awards

• 2019 Best Thesis: Matthias Senker won the price of the Association of Friends of TU Darmstadt “for the best thesis at the chair of Cryptography and Privacy Engineering (ENCRYPTO) 2018” for his master thesis “PSI Meets Signal: Integrating a Malicious-Secure Private Contact Discovery Solution in an Open-Source Instant Messaging Service”.
• 2016 Finalist of German Prize for IT-Security: Our research on “Practical Private Set Intersection” by Michael Zohner, Benny Pinkas (Bar-Ilan University, Israel) and Thomas Schneider was among the 9 finalists selected from 45 submissions to the 6. German Prize for IT-Security 2016.
• 2015 CeBIT 2015: Our PSI research was showcased at the booth of the BMBF at CeBIT 2015.

Publications (selection)

• D. Kales, C. Rechberger, T. Schneider, M. Senker, C. Weinert. Mobile private contact discovery at scale. In 28. USENIX Security Symposium (USENIX Security'19), 2019. Website: https://contact-discovery.github.io. Acceptance rate 16.2%. CORE rank A*.
• B. Pinkas, T. Schneider, O. Tkachenko, A. Yanai. Efficient circuit-based PSI with linear communication. In 38. Advances in Cryptology – EUROCRYPT'19, 2019. Code: https://encrypto.de/code/OPPRF-PSI. Acceptance rate 23.2%. CORE rank A*.
• B. Pinkas, T. Schneider, C. Weinert, U. Wieder. Efficient circuit-based PSI via cuckoo hashing. In 37. Advances in Cryptology – EUROCRYPT'18, 2018. Acceptance rate 23.0%. CORE rank A*.
• B. Pinkas, T. Schneider, M. Zohner. Scalable private set intersection based on OT extension. ACM Transactions on Privacy and Security (TOPS), 2018. Code: https://encrypto.de/code/JournalPSI. CORE rank A.
• Á. Kiss, J. Liu, T. Schneider, N. Asokan, B. Pinkas. Private set intersection for unequal set sizes with mobile applications. Proceedings on Privacy Enhancing Technologies (PoPETs), 2017. Code: https://encrypto.de/code/MobilePSI. Acceptance rate 21.7%. CORE rank B.
• B. Pinkas, T. Schneider, G. Segev, M. Zohner. Phasing: Private set intersection using permutation-based hashing. In 24. USENIX Security Symposium (USENIX Security'15), 2015. Code: https://encrypto.de/code/PSI. Acceptance rate 15.7%. CORE rank A*.
• B. Pinkas, T. Schneider, M. Zohner. Faster private set intersection based on OT extension. In 23. USENIX Security Symposium (USENIX Security'14), 2014. Code: https://encrypto.de/code/PSI. Acceptance rate 19.1%. CORE rank A*.
• M. Fischlin, B. Pinkas, A.-R. Sadeghi, T. Schneider, I. Visconti. Secure set intersection with untrusted hardware tokens. In 11. Cryptographers' Track at the RSA Conference (CT-RSA'11), 2011. Acceptance rate 29.9%. CORE rank B.

Private function evaluation allows to securely evaluate a private function on private data while protecting both the function and the data. This has many applications such as user-specific insurance tarifs or private ML inference that also protects the ML models.

Awards

• 2018 Heidelberg Laureate Forum: Ágnes Kiss was invited to the Heidelberg Laureate Forum 2018 for her outstanding research on Private Function Evaluation.
• 2018 CAST IT Security Award: Daniel Günther with his work on “Valiant’s Universal Circuit – Towards a Modular Construction and Implementation” won the first prize among three finalists in the category “Best Bachelor Thesis” at the CAST IT Security Award 2018.

Publications (selection)

• M. Holz, Á. Kiss, D. Rathee, T.Schneider. Linear-complexity private function evaluation is practical. 25. European Symposium on Research in Computer Security (ESORICS), 2020. Acceptance rate 19.7%. Core rank A.
• M. Y. Alhassan, D. Günther, Á. Kiss, T. Schneider. Efficient and scalable universal circuits. Journal of Cryptology (JoC), 2020. Code: https://encrypto.de/code/UC. CORE rank A*.
• Á. Kiss, M. Naderpour, J. Liu, N. Asokan, T. Schneider. SoK: Modular and efficient private decision tree evaluation. Proceedings on Privacy Enhancing Technologies (PoPETs), 2019. Code: https://encrypto.de/code/PDTE. Acceptance rate 21.1%. CORE rank B.
• D. Günther, Á. Kiss, T. Schneider. More efficient universal circuit constructions. In 23. Advances in Cryptology – ASIACRYPT'17, 2017. Code: https://encrypto.de/code/UC. Acceptance rate 27.6%. CORE rank A.
• Á. Kiss, T. Schneider. Valiant's universal circuit is practical. In 35. Advances in Cryptology – EUROCRYPT'16, 2016. Code: https://encrypto.de/code/UC. Acceptance rate 22.6%. CORE rank A*.
• M. Barni, P. Failla, R. Lazzeretti, A.-R. Sadeghi, T. Schneider. Privacy-preserving ECG classification with branching programs and neural networks. IEEE Transactions on Information Forensics and Security (TIFS), 2011. CORE rank A.
• M. Barni, P. Failla, V. Kolesnikov, R. Lazzeretti, A.-R. Sadeghi, T. Schneider. Secure evaluation of private linear branching programs with medical applications. In 14. European Symposium on Research in Computer Security (ESORICS'09), 2009. Acceptance rate 19.1%. CORE rank A.
• A. Paus, A.-R. Sadeghi, T. Schneider. Practical secure evaluation of semi-private functions. In 7. International Conference on Applied Cryptography and Network Security (ACNS'09), 2009. Code: https://encrypto.de/code/FairplaySPF. Acceptance rate 21.3%. CORE rank B.
• A.-R. Sadeghi, T. Schneider. Generalized universal circuits for secure evaluation of private functions with application to data classification. In 11. International Conference on Information Security and Cryptology (ICISC'08), 2008. Acceptance rate 19.8%. CORE rank B.
• V. Kolesnikov, T. Schneider. A practical universal circuit construction and secure evaluation of private functions. In 12. International Conference on Financial Cryptography and Data Security (FC'08), 2008. Code: https://encrypto.de/code/FairplayPF. Acceptance rate 19.1%. CORE rank B.

We have strong expertise in applying cryptographic protocols to improve privacy in real-world applications. This often involves exciting and very fruitful interdisciplinary research with other areas.

Awards

• 2019 Best Dissertation: Daniel Demmler won the price of the Association of Friends of TU Darmstadt “for excellent scientific work for the best dissertation in the area of computer science 2018” for his dissertation “Towards Practical Privacy-Preserving Protocols”.

Publications (selection)

• A. Treiber, A. Nautsch, J. Kolberg, T. Schneider, C. Busch. Privacy-preserving PLDA speaker verification using outsourced secure computation. Speech Communication, 2019. CORE rank A.
• A. Nautsch, A. Jiménez, A. Treiber, J. Kolberg, C. Jasserand, E. Kindt, H. Delgado, M. Todisco, M. A. Hmani, A. Mtibaa, M. A. Abdelraheem, A. Abad, F. Teixeira, D. Matrouf, M. Gomez-Barrero, D. Petrovska-Delacrétaz, G. Chollet, N. Evans, T. Schneider, J.-F. Bonastre, B. Raj, I. Trancoso, C. Busch. Preserving privacy in speaker and speech characterisation. Computer Speech and Language (CSL), 2019. CORE rank A.
• A. Nautsch, J. Patino, A. Treiber, T. Stafylakis, P. Mizera, M. Todisco, T. Schneider, N. Evans. Privacy-preserving speaker recognition with cohort score normalisation. In 20. Annual Conference of the International Speech Communication Association (INTERSPEECH'19), 2019. Acceptance rate 49.3%. CORE rank A.
• K. Järvinen, H. Leppäkoski, E. S. Lohan, P. Richter, T. Schneider, O. Tkachenko, Z. Yang. PILOT: Practical privacy-preserving Indoor Localization using OuTsourcing. In 4. IEEE European Symposium on Security and Privacy (EuroS&P'19), 2019. Acceptance rate 20.0%.
• O. Tkachenko, C. Weinert, T. Schneider, K. Hamacher. Large-scale privacy-preserving statistical computations for distributed genome-wide association studies. In 13. ACM Asia Conference on Information, Computer and Communications Security (ASIACCS'18), 2018. Acceptance rate 16.8%. CORE rank B.
• M. Chiesa, D. Demmler, M. Canini, M. Schapira, T. Schneider. SIXPACK: Securing Internet eXchange Points Against Curious onlooKers. In 13. International Conference on emerging Networking EXperiments and Technologies (CoNEXT'17), 2017. Acceptance rate 18.1%. CORE rank A.
• M. Albrecht, C. Rechberger, T. Schneider, T. Tiessen, M. Zohner. Ciphers for MPC and FHE. In 34. Advances in Cryptology – EUROCRYPT'15, 2015. Acceptance rate 29.4%. CORE rank A*.
• S. Bugiel, S. Nürnberger, A.-R. Sadeghi, T. Schneider. Twin Clouds: Secure cloud computing with low latency. In 12. Communications and Multimedia Security Conference (CMS'11), 2011. Best Paper Award. Acceptance rate 21.2%. CORE rank C.
• Ahmad-Reza Sadeghi, Thomas Schneider, Immo Wehrenberg. Efficient privacy-preserving face recognition. In 12. International Conference on Information Security and Cryptology (ICISC'09), 2009. Acceptance rate 19.8%. CORE rank B.

We improve the efficiency and practicality of cryptographic protocols and in particular of secure computation protocols.

Publications (selection)

• N. Büscher, D. Demmler, N. P. Karvelas, S. Katzenbeisser, J. Krämer, D. Rathee, T. Schneider, P. Struck. Secure two-party computation in a quantum world. In 18. International Conference on Applied Cryptography and Network Security (ACNS'20), 2020. CORE rank B.
• G. Asharov, Y. Lindell, T. Schneider, M. Zohner. More efficient oblivious transfer extensions. Journal of Cryptology (JoC), 2017. CORE rank A*.
• J. B. Nielsen, T. Schneider, R. Trifiletti. Constant round maliciously secure 2PC with function-independent preprocessing using LEGO. In 24. Annual Network and Distributed System Security Symposium (NDSS'17), 2017. Acceptance rate 16.1%. CORE rank A*.
• G. Asharov, Y. Lindell, T. Schneider, M. Zohner. More efficient oblivious transfer extensions with security for malicious adversaries. In 34. Advances in Cryptology – EUROCRYPT'15, 2015. Code: https://encrypto.de/code/OTExtension. Acceptance rate 29.4%. CORE rank A*.
• G. Asharov, Y. Lindell, T. Schneider, M. Zohner. More efficient oblivious transfer and extensions for faster secure computation. In 20. ACM Conference on Computer and Communications Security (CCS'13), 2013. Code: https://encrypto.de/code/OTExtension. Acceptance rate 19.8%. CORE rank A*.
• B. Pinkas, T. Schneider, N. P. Smart, S. C. Williams. Secure two-party computation is practical. In 15. Advances in Cryptology – ASIACRYPT'09, 2009. Acceptance rate 13.7%. CORE rank A.
• V. Kolesnikov, T. Schneider. Improved garbled circuit: Free XOR gates and applications. In 35. International Colloquium on Automata, Languages and Programming (ICALP'08), 2008. Acceptance rate 30%. CORE rank A.

Hardware-assisted cryptographic protocols allow to improve the efficiency and/or security of cryptographic protocols by using trusted hardware such as smartcards or trusted execution environments like Intel SGX or ARM TrustZone or hardware accelerators.

Publications (selection)

• S. P. Bayerl, T. Frassetto, P. Jauernig, K. Riedhammer, A.-R. Sadeghi, T. Schneider, E. Stapf, C. Weinert. Offline model guard: Secure and private ML on mobile devices. In 23. Design, Automation & Test in Europe Conference & Exhibition (DATE'20), 2020. Acceptance rate 26%. CORE rank B.
• S. Felsen, Á. Kiss, T. Schneider, C. Weinert. Secure and private function evaluation with Intel SGX. In 10. ACM Cloud Computing Security Workshop (CCSW'19), 2019. Acceptance rate 37.5%.
• F. Brasser, T. Frassetto, K. Riedhammer, A.-R. Sadeghi, T. Schneider, C. Weinert. VoiceGuard: Secure and private speech processing. In 19. Annual Conference of the International Speech Communication Association (INTERSPEECH'18), 2018. Acceptance rate 54%. CORE rank A.
• E. M. Songhori, S. Zeitouni, G. Dessouky, T. Schneider, A.-R. Sadeghi, F. Koushanfar. GarbledCPU: A MIPS processor for secure computation in hardware. In 53. Annual Design Automation Conference (DAC'16), 2016. Acceptance rate 17.4%. CORE rank A.
• D. Demmler, T. Schneider, M. Zohner. Ad-hoc secure two-party computation on mobile devices using hardware tokens. In 23. USENIX Security Symposium (USENIX Security'14), 2014. Acceptance rate 19.1%. CORE rank A*.
• K. Järvinen, V. Kolesnikov, A.-R. Sadeghi, T. Schneider. Garbled circuits for leakage-resilience: Hardware implementation and evaluation of one-time programs. In 12. International Workshop on Cryptographic Hardware and Embedded Systems (CHES'10), 2010. Acceptance rate 27.8%. CORE rank A.
• K. Järvinen, V. Kolesnikov, A.-R. Sadeghi, T. Schneider. Embedded SFE: Offloading server and network using hardware tokens. In 14. International Conference on Financial Cryptography and Data Security (FC'10), 2010. Acceptance rate 14.6%. CORE rank B.

We analyze and attack the privacy and security of real-world systems and research papers and propose fixes and alternatives.

Publications (selection)

• C. Hagen, C. Weinert, C. Sendner, A. Dmitrienko, T. Schneider. All the numbers are US: Large-scale abuse of contact discovery in mobile messengers. In 28. Annual Network and Distributed System Security Symposium (NDSS'21), 2021. Website: https://contact-discovery.github.io. CORE rank A*.
• T. Schneider, A. Treiber. A comment on privacy-preserving scalar product protocols as proposed in “SPOC”. IEEE Transactions on Parallel and Distributed Systems (TPDS), 2020. Code: https://encrypto.de/code/SPOCattack. CORE rank A*.
• M. Schneider, T. Schneider. Notes on non-interactive secure comparison in “Image feature extraction in the encrypted domain with privacy-preserving SIFT". In 2. ACM Workshop on Information Hiding and Multimedia Security (IH&MMSEC'14), 2014. Acceptance rate 37.5%. CORE rank C.
• S. Bugiel, S. Nürnberger, T. Pöppelmann, A.-R. Sadeghi, T. Schneider. AmazonIA: When elasticity snaps back. In 18. ACM Conference on Computer and Communications Security (CCS'11), 2011. Acceptance rate 14.0%. CORE rank A*.